Android - Execution failed for task ':app:dexDebug'

I have a problem when compiling my project, I get the error Execution failed for task ':app:dexDebug'. Error:Execution failed for task ':app:dexDebug'.

com.android.ide.common.internal.LoggedErrorException: Failed to run command: C:\Users\Diana\AppData\Local\Android\sdk\build-tools\21.1.2\dx.bat --dex --no-optimize --output C:\Users\Diana\Downloads\VoiceTranslator\app\build\intermediates\dex\debug --input-list=C:\Users\Diana\Downloads\VoiceTranslator\app\build\intermediates\tmp\dex\debug\inputList.txt Error Code: 2 Output: UNEXPECTED TOP-LEVEL EXCEPTION: com.android.dex.DexException: Multiple dex files define Landroid/support/v4/accessibilityservice/AccessibilityServiceInfoCompatIcs; at com.android.dx.merge.DexMerger.readSortableTypes(DexMerger.java:596) at com.android.dx.merge.DexMerger.getSortedTypes(DexMerger.java:554) at com.android.dx.merge.DexMerger.mergeClassDefs(DexMerger.java:535) at com.android.dx.merge.DexMerger.mergeDexes(DexMerger.java:171) at com.android.dx.merge.DexMerger.merge(DexMerger.java:189) at com.android.dx.command.dexer.Main.mergeLibraryDexBuffers(Main.java:454) at com.android.dx.command.dexer.Main.runMonoDex(Main.java:303) at com.android.dx.command.dexer.Main.run(Main.java:246) at com.android.dx.command.dexer.Main.main(Main.java:215) at com.android.dx.command.Main.main(Main.java:106)

I know this question has been asked many times but I have tried the solutions from there and none of them works in my case.

This is my build.gradle

apply plugin: 'com.android.application'

android {
    compileSdkVersion 22
    buildToolsVersion "21.1.2"

    defaultConfig {
        applicationId "imp.translator.diana.voicetranslator"
        minSdkVersion 9
        targetSdkVersion 22
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:22.2.0'
    compile files('libs/android-support-v4.jar', 'libs/microsoft-translator-java-api-0.6.1-jar-with-dependencies.jar')
}

Any ideas what might be wrong here? Any tip would be appreciated!